The objective of this research is to understand the intrinsic ongoing functionality of the human brain present even in the absence of tasks or stimuli. Specifically, the current study will characterize the functional relevance of intrinsic or spontaneous fluctuations in the fMRI BOLD signal. The effect of these spontaneous fluctuations on task-related BOLD responses as well as the influence of spontaneous fluctuations on behavior will be examined. Determining the relationship between spontaneous fluctuations in neural activity, the neuronal response to a stimulus, and the resulting behavior is critical to understanding the operation of the brain. Further, the functional relevance of spontaneous BOLD fluctuations is important for understanding reported disturbances in these fluctuations in different pathological conditions.